The present invention relates to a method of calibrating sensors and more particularly to a method of calibrating a potentiometric sensor used for sensing the position of a clutch pedal in a microprocessor controlled transmission system.
Commonly owned copending application Ser. No. 07/710,360 entitled Transmission Speed Matching control, discloses a microprocessor controlled off-road vehicle transmission wherein a clutch pedal is mechanically linked to a sensing potentiometer so that the voltage output from the potentiometer may be sensed to determine the position of the clutch pedal. The analog voltage output of the potentiometer is digitized by the microprocessor and compared with stored threshold values to determine when the clutch pedal is fully depressed, or when it is depressed below an intermediate threshold point or released above an intermediate threshold point.
Because there is a lack of uniformity between sensors and between linkages which mechanically link a clutch pedal to a sensor, the sensor in each system has to be individually calibrated after being initially installed. Furthermore, tolerances, aging, wear and other variations in a sensor and any associated linkage results in a lack of sensor calibration and periodic recalibration is required to insure that the sensor output signal accurately reflects the condition sensed. The recalibration procedure is not easily carried out by the average individual and, of course, requires special electrical test equipment.